Vapor lamp and radiator



April 23, 1963 L. KATZ 7 3,087,083

VAPOR LAMP AND RADIATOR Filed Jan. 50, 1961 IN V EN TOR.

leawarof I 42 United States Patent 3,087,083 VAPOR LAMP AND RADIATORLeonhard Katz, Woburn, Mass., assignor to Astro Dynamics, Inc.,Cambridge, Mass., a corporation of Massachusetts Filed Jan. 30, 1961,Ser. No. 85,792 1 Claim. (Cl. 313-44) 4 While this invention isapplicable to any lamp contaming material which has to be vaporized inuse, it is particularly applicable to mercury vapor lamps of the highoutput type which have a heater in each end to vaporize the mercurywhile in use. Ordinarily these lamps contain argon or other inert gas inaddition to the mercury. Owing to their high output these lamps tend tooverheat, which reduces their efficiency.

Objects of the present invention are to prevent overheating of the lampsand to cause them to operate at maximum efliciency, withoutsubstantially obstructing the emission of light. Other objects are toprovide a cooling device which is simple and economical in constructionand which can be applied to a lamp quickly and easily.

The present invention involves the combination of a tube containingmercury or the like, a heater in the tube to vaporize the mercury andcooling means juxtaposed to the tube to maintain a limited area of theinterior of the tube at a low temperature, thereby to limit the vaporpressure of the mercury in the tube. Preferably the tube is elongate andhas a heater in each end and the cooling means is located intermediatethe heaters. In the preferred embodiment the cooling means comprises ametal radiator fitting over the tube. Preferably the radiator comprisesa ring having a narrow annular surface bearing on the tube, the ringbeing wider than the surface and having a plurality of fins on its outersurface to radiate heat, the ring being split and having a diameterslightly less than the outside of the tube so as yieldingly to bear onthe tube.

For the purpose of illustration a typical embodiment is shown in theaccompanying drawings in which:

FIG. 1 is aside elevation;

FIG. 2 is a section on line 2-2 of FIG. 1;

FIG. 3 is a section on line 3-3 of FIG. 1; and

FIG. 4 is a section on line 44 of FIG. 3,

The particular embodiment of the invention chosen for the purpose ofillustration comprises an elongate glass tube 1 having at each end are-entrant portion 2, a cap '3, a ring 4 for holding the cap on thetube, a heating filament 5 supported on conductors 6 and 7, a metal disk8 having openings to receive the conductors 6 and 7, the disk being fastto the conductor 7 at 9 and being insulated from the conductor 6 bymeans of a circular insulator 1'0, and contacts 11 and 12 mounted on thecap 3 and connected to the conductors 6 and 7. This is a standard tubemade and sold by Sylvania Corporation under the designation PowertubeF48T12-CW-VHO.

According to this invention a metal ring 13 is slipped over the tubefrom one end. Extending around the inside of the ring is an annular rib15 and projecting outwardly from the ring are fins 16 to radiate heat.The ring is split at 14 and the diameter of the surface of rib 15 isslightly less than that of the tube so that the rib is pressedyieldingly against the tube to make good contact with the tube and holdthe ring in position on the tube.

For maximum efficiency of the aforesaid tube the heat radiated should beonly enough to keep one spot of the tube at a temperature approximately40 C. in an ambient of 25 C. which will control the vapor pressure ofthe mercury at the desired level. When the ring is made of aluminum therib 15 should be about one-eighth inch wide and the other dimensions inproportion.

It should be understood that the present invention is for the purpose ofillustration only and that this invention includes all modifications andequivalents which fall within the scope of the appended claim.

I claim:

For use with a tubular mercury vapor lamp, a split ring radiatorcomprising a split ring body part having on its inner surface acircumferential band of reduced area, and, on the outer surface of thering body, a plurality of disk-shaped fins which are coaxial with thering.

References Cited in the file of this patent UNITED STATES PATENTS1,897,586 Pirani Feb. 14, 1933 1,924,368 McCullough Aug. 29, 19332,966,602 Waymouth Dec. 27, 1960

